Periodontal disease is a disease wherein soft tissue around teeth and alveolar bone are destroyed by chronic inflammation caused by periodontal pathogens, so that the gum bleeds and teeth are loose and ultimately lost. Periodontal pathogens include Prevotella intermedia, Actinomyces israelii, Fusobacterium nucleatum, etc.
Efforts have been made continuously to eliminate plaque-forming bacteria using antibiotics such as penicillin in order to prevent periodontal disease. However, these antibiotics are not used in clinical practice because of antibiotic-resistant bacteria created when these antibiotics are used for a long period of time. To overcome this disadvantage, various methods including the use of fluorine-based compounds or automatic dental cleaning devices have been developed, but the effects thereof are insignificant. In clinical practice, a mouthwash containing chlorohexidine is used. In addition, plasters, ointments and the like, which contain minocycline, are used.
Meanwhile, atopic dermatitis is a disease that is widely distributed worldwide, and 3-5% of children 5 years old or younger are suffering from this disease. In general, atopic dermatitis begins in infancy and childhood, 90% or more of patients with atopic dermatitis show symptoms before the age of 5 years.
In the past, atopic dermatitis was thought as a kind of allergy. However, as the consideration of atopic dermatitis in terms of non-allergy is expanded, an approach to the cause and solution of eczema reactions is being made. In a process of examining various skin physiological functions in patients having this disease, the patients show abnormal functions, including a reduction in perspiration, a reduction in sebum secretion, an abnormal skin vascular reaction and a dry skin. Thus, in terms of non-allergy, a new opinion that a dry skin is most significant as the condition of atopic dermatitis is being suggested.
When a dry skin is formed, the barrier function of the skin surface will be lost, the penetration of external stimuli or allergens into the skin will be easy, and the skin will have rejection reaction to the penetrated materials. Atopic dermatitis leads to severe symptoms due to secondary bacterial infection caused by scratching of an itchy skin area. Atopic patients have a high possibility of exposure to bacterial infection as a result of long-term scratching and being dried. Main bacteria that cause secondary bacterial infection in atopic dermatitis patients are Streptococcus bacteria, and several kinds of microorganisms infect atopic dermatitis patients to cause reactions such as inflammation. Recent reports indicate that the endotoxin of such bacteria stimulates the immune system of the human body to release allergy-causing chemicals, thereby worsening atopic dermatitis. In other words, these bacteria themselves act as allergens.
Patients having atopic skin symptoms are treated with steroid ointments and internal medicines (including injectable solutions) in hospitals and pharmacies. However, it is known that the use of steroids as internal medicines or injectable solutions causes skin adverse effects, including subcutaneous congestion, pigmentation, hair loss, itching, and facial erythma, adverse effects in the endocrine system, including secondary adrenocortical insufficiency and diabetes, adverse effects in the digestive system, including peptic ulcer and gastritis, adverse effects in the psychoneural system, including melancholia and headache, adverse effects musculoskeletal system, including osteoporosis, adverse effects of protein metabolism, including nitrogen imbalance, adverse effects in the electrolyte system, including a rise in blood pressure, and adverse effects in the eye, including ocular hypertension and glaucoma. In addition, it was reported that the use of steroid-based ointments causes severe adverse effects, including skin infection, steroidal acne, steroidal dermatitis, and the inhibition of pituitary-adrenal function.
Particularly, it is evident that the adverse effects of steroids in infant patients are very severe compared to those in adults. Due to such adverse effects, there are increasing attempts to find new methods for treating atopic dermatitis. In addition to the use of medicines, cosmetics for atopic dermatitis are being used, and these products are being actively developed. The first generation products for atopic dermatitis were based on natural oils and mineral components, and the second generation products mainly contain ceramide and natural moisturizing factors. However, the first and second generation products focus on the maintenance of skin moisture, and thus there is a limitation in improvement of atopic skin. Thus, it is essential that proper antibiotic substances is used for the treatment of atopic dermatitis.
Accordingly, the present inventors have made extensive efforts to develop a peptide having antibacterial or anti-inflammatory activity against periodontal pathogens and skin parasitic bacteria, and as a result, have found that a peptide derived from human beta-defensin, platelet-derived growth factor or heparin-binding epidermal growth factor is effective for the treatment of periodontal disease and the alleviation of atopic dermatitis, thereby completing the present invention.